Question

The adjacent diagram shows a heavy roller, with its axle at $O$, which is to be raised on a pavement $XY$. If there is friction between the roller and pavement, show by an arrow on the diagram the point of application and the direction of force to be applied.

Answer 1

Hint: Friction is the force exerted by two surfaces moving (or attempting to slide) over one another. When you try to drive a book onto the board, for example, friction makes it impossible. Friction often acts in the opposite direction from where the target is going or attempting to travel.

Complete answer:
The force that can cause an object to spin around an axis is measured in torque. In linear kinematics, force is what allows an object to accelerate. Torque is also responsible for angular acceleration. As a result, torque can be defined as the linear force's rotational counterpart.

The axis of rotation is the position at which the object rotates. Torque is the inclination of a force to transform or rotate in mechanics. Torque is defined using a variety of terminologies, including moment and moment of power. The torque can be static or dynamic. A torque that does not generate an angular acceleration is known as static torque.
$\tau \propto r$

Calculating the degree of the torque is as straightforward as determining the lever arm and multiplying it by the applied force. $r$ should be maximum to get maximum torque while holding force to a minimum. Force $F$ must be applied in the direction shown in the diagram.

Note: A rotational or twisting force is expressed by torque. Torque is created as automobiles' engines spin around an axis. It can be compared to a vehicle's power. Torque is what propels a race car from 0 to 60 mph in a matter of seconds. Torque is also what propels large trucks carrying huge loads.